Generally, a blower is a mechanical device that generates energy of a fluid. The blower includes of an impeller that generates a flow, and a casing that guides a flow coming into and going out the impeller.
There are various kinds of methods of dividing the blower and they are divided into an axial blower, a radial blower, and a mixed blower according to the characteristics of the flow passing through the impeller.
For example, a radial type blower is mainly used for increasing a pressure due to a centrifugal force. Therefore, it is widely used where pressure is required rather than flow rate.
Also, in case of a centrifugal type blower, a helical casing is used in such a manner that an inlet flow of the impeller is in a direction of the rotation axis and the outlet flow thereof is in a direction perpendicular to the rotation axis or a tubular casing is used in such a manner that the inlet flow and the outlet flow of the impeller are in a direction of the rotation axis.
A turbo blower, which is a type of centrifugal blower, refers to a centrifugal blower having a relatively high pressure ratio. The impeller is rotated at a high speed in a vessel to radially flow the gas. In the centrifugal blowers using a centrifugal force, it refers to a turbo ventilator having a small pressure ratio and refers to the centrifugal type blower, that is, the turbo blower having a pressure ratio larger than the turbo ventilator.
The turbo blower includes a main body that forms an outer appearance, a driving unit that is provided inside the main body and substantially pressurizes the air, and a control unit that controls the driving of the driving unit. The air, which is introduced into the main body through the air inlet formed at the main body, is pressurized above a certain pressure to be discharged.
However, in the related art, the noise generated in the internal driving unit is largely transmitted to the outside. Also, since the internal structure for properly cooling the internal components of the driving unit is not provided, there are defects in that the lifespan of the internal components is reduced and the durability of the entire driving unit is reduced.
The cooling usually utilizes a method using an intake air or a gas flowing into the impeller. Or, a method of blowing a large amount of air therein through an air gap formed between a rotor and a stator or a cooling hole formed in the stator can be utilized.
In the former method, the power required for cooling is small, but it has a disadvantage that the sensitivity to the impeller is very high because the cooling system itself is closely interlocked with the impeller.
That is, since the structure of the cooling system is changed according to the design shape of the impeller, the degree of freedom of design is greatly restricted.
In addition, there is a problem in that the entire size of the turbo device is increased due to the characteristics of the cooling system.
The latter method has a disadvantage in that the cooling efficiency is very low because it has a structure of blowing a large amount of air therein by a considerable pressure by using a cooling fan.
Accordingly, a cooling system that relies on a cooling fan has a problem of consuming a relatively large amount of power in order to maintain an appropriate level of cooling. Since the introduced air cools the entire interior thereof, it is not enough to provide a regular cooling for each component. As a result, the cooling efficiency thereof is reduced.
On the other hand, a both-end type turbo blower has been developed in the related art, but since impellers are disposed at both sides, there is a spatial limit in installation of a fan, and accordingly, a water cooling type and an impeller intake air type have been used.
In the water cooling type, since the subsidiary materials for cooling such as a pump, a heat exchanger, a water tank, a pipe, etc. are considerably necessary, the cost is increased. Also, in order to affix them thereto, since the separate space is necessary in the package, there is a disadvantage in that the equipment becomes bigger.
In addition, if a leak occurs, it may lead to big accidents owing to the equipment that uses high voltage.
In the method using the impeller intake air, since the intake air cools the internal components to be heated, the impeller inhales the air having low density. Thus, it is smaller than the room temperature in terms of flow rate thereof and the efficiency thereof is lowered.
Further, in order to accurately measure the flow rate, it requires a nozzle. However, there is a drawback in that it is not possible to affix the nozzle thereto.
That is, in the conventional both-end type turbo blower, turbo blower, since it is difficult to configure and install the fan, it has no choice but to use the water cooing method and the air cooling method using the impeller intake air, though the manufacturing cost is increased and the efficiency is lowered.
Therefore, a direct drive-type turbo blower cooling structure for thermal balance is needed.